SNOW-1293828 Updated security policy (#904)

### Description
Security policy information

### Checklist
- [ ] Code compiles correctly
- [ ] Code is formatted according to [Coding
Conventions](../CodingConventions.md)
- [ ] Created tests which fail without the change (if possible)
- [ ] All tests passing (`dotnet test`)
- [x] Extended the README / documentation, if necessary
- [x] Provide JIRA issue id (if possible) or GitHub issue id in PR name

SECURITY.md

@@ -0,0 +1,4 @@
+# Security Policy
+
+Please refer to the Snowflake [HackerOne program](https://hackerone.com/snowflake?type=team) for our security policies and for reporting any security vulnerabilities.
+For other security related questions and concerns, please contact the Snowflake security team at [email protected]